Review of how fish hear could lead to better understanding of how fish are affected by sound disturbances in the ocean

July 28, 2020

A new literature review published by University of Maryland Center for Environmental Science scientists is the first of its kind to bring together a broad pool of studies of thousands of species of fish to help understand how fish hear. The review evaluated over 100 scientific studies and confirmed that fish with more complex swim bladders were able to hear a wider range of sound frequencies. This information will be useful for future research as a starting point to make predictions on how fish may be affected by sound disturbance in the environment.

Increases in commercial development in the ocean, such as growing shipping channels and growing ocean infrastructure, increase ocean noise which may be having negative effects on fish populations. The effects increased noise has on fish can range from affecting movement patterns to damaging their auditory structures.

Caroline Wiernicki, a recent graduate of UMCES’ Chesapeake Biological Laboratory, compiled the findings from a series of 60 scientific papers, containing over 100 individual studies, and organized the findings based on the complexity of the hearing systems of fish species being evaluated. The end result was a complete list of ranges of fish hearing frequencies that researchers can use as a basis for future studies.

“Our paper is the first attempt to look back at a diverse set of data and try to pull valuable information from it that could be used to inform future management decisions in terms of fish’s auditory abilities,” said Wiernicki.

Fish are able to hear through a variety of structures evolved millions of years ago. With tens of thousands of different species of fish, there is a range of what hearing structures different species have. While all fish have a unique lateral line system—a group of sensory organs—fish hearing is better in species that have more complex hearing systems, such as the presence of an inner ear and swim bladders. Swim bladders are most known for regulating fish buoyancy but also have a role in how fish hear.

“The ocean is getting busier as we use it more. There’s a need to look at whether an additional noise will have a significant impact on the surrounding marine community. As we use the ocean more and make more noise, we need to have tools grounded in science and research to figure out how those noises will affect the surrounding environment,” said Wiernicki

Managers will now be able to look that the existing pool of species that research has been conducted on and figure out a range of what other fish might be hearing based on their auditory structures, such as the ear bone pictured here.

Commercial development in the oceans is not the only auditory factor that may affect fish. As the effects of climate change become increasingly apparent through record-breaking summers and sea-level rise, another result of climate change is increased frequency and strength of storms. Larger more powerful—and noisier—storms may also affect a wide range of fish species.

Managers will now be able to look that the existing pool of species that research has been conducted on and figure out a range of what other fish might be hearing based on their auditory structures.

Using studies from across the globe, Wiernicki evaluated attempted to find what frequencies different fishes could hear. Quality control measures were put into place to ensure that reliable data and methods were used throughout these studies but the statistical work made it possible to put these studies on an equal playing field and discover the broader trends. Review authors looked at a range of variables in each study, including its methods, the type of sound they were measuring, and how many fish were studied to create commonalities between studies to draw out greater conclusions.

Upon researching whether black sea bass could hear the auditory levels produced by there were no studies done at the time. To fill the void of information on how fish hear and organize the data that was out there, Wiernicki created this review.

 “The Effect of Swim Bladder Presence and Morphology on Sound Frequency Detection for Fishes” was published in Fisheries Science & Aquaculture